Study On Dry Matter Accumulation And Nutrient Absorption Of Soybean Cultivars Released In Different Decades

This study used representative soybean[Glycine max (L.) Merr.] cultivars from two pedigrees’Williams’and’Amsoy’developed in different, breeding programs of Ohio and Liaoning, China, which were at the same latitude. This field experiment was conducted at the research farm of Shenyang Agricultural University in 2013 and 2014. This paper compared photosynthetic traits, dry matter accumulation and distribution, nutrient accumulation and distribution, the yield and quality of soybean cultivars developed in different years. This paper intended to reveal the evolutionary trends of photosynthetic traits, dry matter accumulation and nutrient accumulation and distribution as well as yield incensement, trying to provide theoretical foundation for soybean breeding and high-yield cultivation. The results were as follows.1 Comparison on photosynthetic traits of soybean cultivars developed in different yearsThe results showed that the trends of Liaoning and Ohio soybean cultivars photosynthetic traits were consistent with seed yield improvements, the leaf area index, leaf greenness, net photosynthetic rate, stomata conductance and transpiration index increased with the progress of breeding, however, intercellular CO2 concentration decreased. Leaf greenness was highly significantly positive correlated with soybean yield at seedling stage, flowering stage and medium stage of grain filling, while transpiration was significantly highly negatively correlated with the seed yield. Net photosynthetic.rate of Ohio current cultivars were decreased less at late growth stage, while Liaoning current cultivars were decreased larger. At seedling stage the stomata conductance of Liaoning current cultivars was increased significantly, however, intercellular CO2 concentration of Ohio current cultivars was reduced significantly at flowering stage and late stage of seed filling, transpiration index of Liaoning current cultivars was higher than Ohio current cultivars in the whole growth stages.Leaf greenness at the seedling stage, flowering stage, medium stage of seed filling was significantly positive correlated with yield; Leaf area index, net photosynthetic rate and stomata conductance in seed filling stage was significantly positive correlated with yield, intercellular CO2 concentration in the seedling stage was significantly negative correlated with yield; Transpiration rate at the seedling stage, flowering and seed filling stage was significantly negative correlated with yield.2 Comparison on dry matter accumulation and distribution of soybean cultivars developed in different yearsWith the advance of crop growth, Plant biomass production increased at the mature stage. Stem mass accounted for total dry weight ratio showed rise first and fall later, and reached the maximum at the medium stage of seed filling. Leaf and root dry weight accounted for total dry weight ratio showed falling trend, petiole dry weight accounted for total dry weight showed rise first and fall later, and reached the maximum at flowering stage. From the medium stage of seed filling to the mature stage, pod wall and grain dry weight accounted for total dry weight showed increasing trend, and reached the maximum at the mature stage.Compared with the common parent species, biological yield per plant of Liaoning and Ohio varieties is increasing, and Liaoning varieties increased by a large margin, increased by 3.6% and 11.5% respectively. Liaoning varieties stem weight and leaf dry weight accounted for the proportion of total dry weight decreased, where skin dry pod weight, grain dry weight and root dry weight of the total dry weight accounted for the proportion increased; Compared with the mid-Ohio varieties, Ohio currrent varieties stem dry weight accounted for total dry weight showed a significant increasing trend at flowering and mature stage, petiole dry weight accounted for whole plant dry weight increased whereas leaves, pods leather, grain dry weight accounting for the proportion of the total dry weight decreased;Compared with the same year varieties, biological yield per plant of Liaoning varieties are higher than Ohio varieties. Stems and leaf dry weight accounted for the total dry weight of Liaoning middle varieties are higher than the Ohio middle varieties. Stem and leaf dry weight accounted for the total dry weight of Ohio currrent varieties are higher than Liaoning currrent varieties. 3 Comparison on photosynthetic traits of soybean cultivars developed in different yearsWith the advance of growth stages, nutrient accumulation in the middle stage of seed filling and mature stage appeared two peaks. NPK content in stem, phosphorus and potassium content in leaves and potassium content in petiole reached the maximum at the seedling stage. Nitrogen content in leaves and phosphorus content in petiole reaches a maximum at flowering stage, and then decreases. Late grain fertility nitrogen and phosphorus content in grain continues increasing at late growth stage, and reached the maximum at maturity stage and higher than other organs. Nitrogen content in skin pod decreased, phosphorus and potassium content reached maximized at seed filling stage.With the soybean varieties modified, nutrients required for the production of unit weight grain number gradually reduced, stems and grain nitrogen content of Liaoning and Ohio varieties are higher than their common parental varieties, whereas phosphorus and potassium content of stem, potassium content of leaf and petiole are lower than their common parent varieties. Nitrogen and phosphorus content in stems and petioles, phosphorus content in leaves and grain and pod potassium content of Liaoning middle varieties are higher than in Liaoning currrent varieties. Nitrogen and potassium content in leaf and grmain, nitrogen and phosphorus content in pod shell and potassium content in stem and petiole are lower than Liaoning currrent varieties. Nutrient content in grain, nitrogen and phosphorus content in leaves and pods shell, and potassium content in leaves of the Ohio middle varieties are higher than the Ohio currrent varieties. NPK content in stems and petioles, phosphorus content in grain and potassium content in pod shell are lower than Ohio currrent varietiesCompared with the same year varieties, nitrogen and potassium content in grain of Liaoning varieties are higher than Ohio varieties. Nitrogen content in leaves, potassium content in pod shell and phosphorus content in grain of Liaoning middle varieties are significantly higher than the Ohio middle varieties. Phosphorus content in leaves potassium content in pod shell and phosphorus content in grain of seed filling stage of Liaoning currrent varieties are higher than Ohio currrent varieties, whereas phosphorus content in grain of mature stage is lower than Ohio currrent varieties.4 Comparison on yield and quality of soybean cultivars developed in different yearsAt the process of cultivar development, pods per plant, seeds per plant,100-seed weight, harvest index and yield increased; Current cultivar of Liaoning yield increased by 45.3%.the improvement of seeds per plant was the main reason for yield increasing of Ohio cultivars, and the main factor for Liaoning cultivars was of bigger 100-seed weight and pods per plant.At the process of cultivar development, protein content and fat content of Liaoning cultivars and Ohio cultivars increased. Liaoning varieties of protein content were significantly increased,43.37% and 43.44% respectively. The Ohio varieties fat content increased significantly,21.05% and 21.20% respectively.